﻿using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.ServiceProcess;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace GPSTK102ProtocolListenerWindowsService
{
    // State object for reading client data asynchronously
    public class StateObject
    {
        // Client socket.
        public Socket workSocket = null;
        public const int BufferSize = 512;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
    }

    partial class GPSTK102ProtocolListenerWindowsService : ServiceBase
    {
        public const string WindowsServiceModel = "TK102B";
        public const int BufferSize = 512;
        // Thread signal.
        public static ManualResetEvent allDone = new ManualResetEvent(false);
        Thread TCPListenerThread = new Thread(StartListening);
        public static bool IsThreadAlive = true;

        //Message Two: imei:354776034235009,tracker,1404171102,,F,170209.000,A,1002.8757,N,08425.7526,W,0.00,;

        // Enum Field
        enum MessageField
        {
            Imei = 0,
            Monitor = 1,
            Datetime = 2,
            NullField = 3,
            Signal = 4,
            Fix = 5,            
            BatteryLevel = 6,            
            Latitude = 7,
            LatitudeHemisphere = 8,             
            Longitude = 9,
            LongitudeHemisphere = 10,                          
            Speed = 11
            
        }

        public GPSTK102ProtocolListenerWindowsService()
        {
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            try
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("--- GPS " + WindowsServiceModel + " Port Listener Starting V1 ---", WindowsServiceModel);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("IP: " + System.Net.Dns.GetHostName(), WindowsServiceModel);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Port: " + Properties.Settings.Default.Port.ToString(), WindowsServiceModel);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Max Connections: " + Properties.Settings.Default.MaxConnections.ToString(), WindowsServiceModel);

                IsThreadAlive = true;
                TCPListenerThread.Start();
            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error..... Message:" + ex.Message + " StackTrace:" + ex.StackTrace, WindowsServiceModel);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("--- GPS " + WindowsServiceModel + " Port Listener Is DOWN", WindowsServiceModel);
            }
        }

        protected override void OnStop()
        {
            IsThreadAlive = false;
            GPSTrackingDBCustom.Log.WindowsServiceLog.Warning("--- GPS " + WindowsServiceModel + " Port Listener Is DOWN ---", WindowsServiceModel);
        }

        public static void StartListening()
        {
            IPEndPoint ep = new IPEndPoint(IPAddress.Any, Properties.Settings.Default.Port);

            // Create a TCP/IP socket for listner.
            Socket listenerSock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            // Bind the socket to the endpoint and wait for listen for incoming connections.
            try
            {
                listenerSock.Bind(ep);
                listenerSock.Listen(Properties.Settings.Default.MaxConnections);

                while (IsThreadAlive)
                {
                    try
                    {
                        // Set the event to nonsignaled state.
                        allDone.Reset();

                        // Start an asynchronous socket to listen for connections.
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Waiting for a connection ...", WindowsServiceModel);
                        listenerSock.BeginAccept(new AsyncCallback(AcceptCallback), listenerSock);

                        // Wait until a connection is made before continuing.
                        allDone.WaitOne();
                    }
                    catch (Exception ex)
                    {
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - StartListening Waiting for a connection ... Message:" + ex.Message, WindowsServiceModel);
                        listenerSock.Shutdown(SocketShutdown.Both);
                        listenerSock.Close();
                    }

                }

            }
            catch (Exception ex)
            {
                IsThreadAlive = false;
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error..... Message:" + ex.Message, WindowsServiceModel);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error(WindowsServiceModel + " Port Listener is DOWN", WindowsServiceModel);
            }
        }

        public static void AcceptCallback(IAsyncResult ar)
        {
            try
            {
                // Signal the main thread to continue.
                allDone.Set();

                // Get the socket that handles the client request.
                Socket listener = (Socket)ar.AsyncState;
                Socket handler = listener.EndAccept(ar);

                // Create the state object.
                StateObject MessageDevice = new StateObject();
                MessageDevice.workSocket = handler;
                handler.BeginReceive(MessageDevice.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), MessageDevice);


            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - AcceptCallback Message:" + ex.Message, WindowsServiceModel);
            }
        }

        public static void ReadCallback(IAsyncResult ar)
        {
            // Retrieve the state object and the handler socket
            // from the asynchronous state object.
            StateObject MessageDevice = (StateObject)ar.AsyncState;
            Socket handler = MessageDevice.workSocket;

            // Read data from the client socket.
            int bytesRead = handler.EndReceive(ar);

            try
            {

                //No Message 
                if (bytesRead <= 0)
                {
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device. No Message", WindowsServiceModel);
                    handler.Shutdown(SocketShutdown.Both);
                    handler.Close();

                    return;
                }

                //Process Message Android
                var New_MessageDevice = MessageDevice.buffer.TakeWhile((v, index) => MessageDevice.buffer.Skip(index).Any(w => w != 0x00)).ToArray();
                string Message = System.Text.UTF8Encoding.UTF8.GetString(New_MessageDevice);

                //Message One: ##,imei:354776034235009,A; 
                //Message Reply: **,imei:354776034235009,B;
                //Message Two: imei:354776034235009,tracker,1404171102,,F,170209.000,A,1002.8757,N,08425.7526,W,0.00,;


                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Message Device: " + Message, WindowsServiceModel);
                string[] MessageArray = Message.Split(new char[] { ',' });

                if (Message.StartsWith("##"))
                {
                    //Send command OK
                    string MessageSend = "LOAD**," + MessageArray[(int)MessageField.Imei + 1] + ",B;";


                    System.Text.ASCIIEncoding Encoding = new ASCIIEncoding();                    
                    SendCommand(handler, Encoding.GetBytes(MessageSend), 2);

                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Message Device: " + Message + "GET GPS Location " + MessageSend, WindowsServiceModel);
                    // Not all data received. Get more.
                    handler.BeginReceive(MessageDevice.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallback), MessageDevice);
                    return;
                }

                if (MessageArray.Length != 13)
                {
                    // Disconnect 
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Message isn't valid", WindowsServiceModel);
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device.", WindowsServiceModel);
                    handler.Shutdown(SocketShutdown.Both);
                    handler.Close();

                    return;
                }

                string Imei = MessageArray[(int)MessageField.Imei];
                string Datetime = DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss");
                string Latitude = MessageArray[(int)MessageField.Latitude];
                string Longitude = MessageArray[(int)MessageField.Longitude];                
                string Speed = MessageArray[(int)MessageField.Speed];                

                //Insert to Database
                GPSTrackingDBV2.Entities.TrackData TrackDataEntity = new GPSTrackingDBV2.Entities.TrackData();
                try
                {
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Inserting track message to database ...", WindowsServiceModel);
                    GPSTrackingDBV2.Entities.TrackDataLastLocation TrackDataLastLocationEntity = new GPSTrackingDBV2.Entities.TrackDataLastLocation();

                    DateTime DateFix = DateTime.ParseExact(Datetime, "dd/MM/yyyy HH:mm:ss", System.Globalization.CultureInfo.CurrentCulture);

                    TrackDataLastLocationEntity.GpsImei = TrackDataEntity.GpsImei = Imei.Substring(5);
                    TrackDataLastLocationEntity.DateTime = TrackDataEntity.DateTime = DateFix;

                    double LatitudeFix = Convert.ToDouble(Latitude);
                    double LongitudeFix = Convert.ToDouble(Longitude);

                    //Convert NMEA
                    //Convert Lat.
                    int LatDegree = Convert.ToInt32(Latitude.Substring(0, 2));
                    double LatMinute = Convert.ToDouble(Latitude.Substring(2));

                    LatMinute = LatDegree + (LatMinute / 60);

                    //Convert Long.
                    int LongDegree = Convert.ToInt32(Longitude.Substring(0, 3));
                    double LongMinute = Convert.ToDouble(Longitude.Substring(3));

                    LongMinute = LongDegree + (LongMinute / 60);
                    LongMinute = LongMinute * -1;

                    LatitudeFix = LatMinute;
                    LongitudeFix = LongMinute;
                    
                    if (Properties.Settings.Default.AutoFixPosition)
                    {
                        LatitudeFix = LatitudeFix - Properties.Settings.Default.FixLatitude;
                        LongitudeFix = LongitudeFix - Properties.Settings.Default.FixLongitude;
                    }

                    TrackDataLastLocationEntity.Latitude = TrackDataEntity.Latitude = LatitudeFix;
                    TrackDataLastLocationEntity.Longitude = TrackDataEntity.Longitude = LongitudeFix;
                    TrackDataLastLocationEntity.Heading = 0;
                    TrackDataLastLocationEntity.Speed = Convert.ToDouble(Speed) * 1.852;

                    GPSTrackingDBV2.Data.DataRepository.TrackDataProvider.Insert(TrackDataEntity);

                    //Update last location  
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Updating last track message location to database ...", WindowsServiceModel);
                    try
                    {
                        GPSTrackingDBV2Custom.Data.DataRepository.TrackDataLastLocationProvider.UpdateOrInsert(TrackDataLastLocationEntity);
                        // Disconnect 
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device.", WindowsServiceModel);
                        handler.Shutdown(SocketShutdown.Both);
                        handler.Close();                       
                    }
                    catch (Exception ex)
                    {
                        GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - Updating last track message:" + ex.Message, WindowsServiceModel);
                        // Disconnect 
                        handler.Shutdown(SocketShutdown.Both);
                        handler.Close();
                    }


                }
                catch (Exception ex)
                {
                    GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - Inserting track message:" + ex.Message, WindowsServiceModel);
                    // Disconnect 
                    handler.Shutdown(SocketShutdown.Both);
                    handler.Close();

                }
            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - Message invalid:" + ex.Message, WindowsServiceModel);
                // Disconnect 
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();
            }
        }

        private static void Send(Socket handler, byte[] MessageSend)
        {
            try
            {
                // Begin sending the data to the remote device.               
                handler.BeginSend(MessageSend, 0, MessageSend.Length, 0, new AsyncCallback(SendCallback), handler);
            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - Send Message:" + ex.Message, WindowsServiceModel);
                // Disconnect 
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();
            }
        }

        private static void SendCallback(IAsyncResult ar)
        {
            // Retrieve the socket from the state object.
            Socket handler = (Socket)ar.AsyncState;
            try
            {
                // Complete sending the data to the remote device.
                //int bytesSent = handler.EndSend(ar);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Disconnected... gps device.", WindowsServiceModel);
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();

            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error - SendCallBack..... " + ex.Message, WindowsServiceModel);
                handler.Shutdown(SocketShutdown.Both);
                handler.Close();
            }
        }


        private static void SendCommand(Socket handler, byte[] MessageSend, int LineNumber)
        {
            // Begin sending the data to the remote device.
            GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Command Send: " + System.Text.UTF8Encoding.UTF8.GetString(MessageSend).Replace("\0", ""), WindowsServiceModel);
            handler.BeginSend(MessageSend, 0, MessageSend.Length, 0, new AsyncCallback(SendCallbackCommand), handler);
        }

        private static void SendCallbackCommand(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket handler = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = handler.EndSend(ar);
                GPSTrackingDBCustom.Log.WindowsServiceLog.Info("Command... Send " + bytesSent.ToString() + " bytes to gps device.", WindowsServiceModel);

            }
            catch (Exception ex)
            {
                GPSTrackingDBCustom.Log.WindowsServiceLog.Error("Error Command..... " + ex.Message, WindowsServiceModel);
            }
        }
    }
}
